1. Field of the Invention
The present invention generally relates to data storage and, more specifically, to systems and methods employing atomic resolution storage (ARS) techniques that facilitate data recovery during failure of one or more data storage system emitters.
2. Background of the Invention
The apparent insatiability of consumers for higher capacity, higher speed memory storage devices has led to the development of memory storage techniques such as atomic resolution storage (ARS). As is known, a storage device employing ARS technology includes a number of electron field emitters that are adapted to write data to and read data from various storage areas of a storage medium. The field emitters, commonly are referred to as "point-emitters", are configured with sharp tips, e.g., each tip including a radius of curvature of approximately one nanometer to hundreds of nanometers.
During operation, a predetermined potential difference is applied between a field emitter and a corresponding gate. Due to the sharp tip of the emitter, an electron beam current is extracted from the emitter towards the storage area. Writing of data from an emitter to a storage area is accomplished by temporarily increasing the power density of the electron beam current to modify the structural state of the surface of the storage area. In contrast, reading data from the storage area is accomplished by observing the effect of the storage area on the electron beam of the emitter, or the effect of the electron beam on the storage area. More specifically, reading typically is accomplished by collecting secondary and/or backscattered electrons when an electron beam, i.e., an electron beam with a lower power density than that of the electron beam utilized for writing data to the storage area, is applied to the storage medium.
An ARS storage medium is formed of material characterized by a structural state that can be changed from crystalline to amorphous by a beam of electrons. Since the amorphous state has a different secondary electron emission coefficient (SEEC) and backscattered electron coefficient (BEC) than the crystalline state, a different number of secondary and backscattered electrons are emitted from each storage area, in response to an electron beam, depending upon the current structural state of that storage area. Thus, by measuring the number of secondary and backscattered electrons, the structural state of the storage area and, therefore, the data stored by the storage area, may be determined.
Heretofore, however, failure of a field emitter may adversely affect the ability of an ARS storage device to retrieve and/or reconstruct data stored in the storage area(s) associated with the failed emitter. Accordingly, there is a need for improved devices, systems and methods that address these and other shortcomings of the prior art.